The purpose of this Core is to provide a common set of state-of-the-art biochemical analyses to Center researchers. The laboratories of the Core will.. provide assessments of hypothalamic-pituitary-adrenal axis function, neurotransmitter (central and peripheral) levels, and antidepressant concentrations to the individual Research Projects of the Emory University Center for the Neuroscience of Mental Disorders. Accurate measurement of these parameters is imperative to fully characterize each of the preclinical and clinical model systems of early life stress and its long-term neurobiological consequences in adults being investigated by the Center. Having these determinations performed by a central facility using a common set of assay modalities will provide the unprecedented opportunity to compare these models across strain and species lines (without introducing the variable of assay incompatibilities). Additionally, having a Core devoted to these analyses will guarantee high quality assay performance, allow for economies-of-scale in the purchase of assay reagents and technician time, and enable Center investigators to more fully concentrate their efforts on the unique aspects of their particular project.